dnet lockup

[amazed]

Trying to make a robust dnet program using only explicit messaging.  Unplug device and communication can

only be re-established by unplugging dnet card  Small example of what i am starting with below. Unable

to determine source of error.

Thankyou for any suggestions  

[JohnM 64]

Hello,

When you say you can only re-establish communication by unplugging the DNet card, do you mean unplugging the DNet cable, or actually taking the PCI card out of the slot and then placing it back in?  If so, can the connection be re-established by resetting the card rather than completely unplugging it (Cntrl+Shift+right-click in MAX)?

Also, does the program hang when the device is unplugged, or just return errors?  Does the program finish and close the resource once the device is unplugged?  If not, it could be trying to open a reference that is already opened.  Do you get an error when trying to re-establish communication?

john m
Applications Engineer

[frankwu]

Hi Amazed,

Your VI has a problem: it tries to reconnect to the device in a while loop without closing the previous connection. What's more, the correct way to stop communication is (1) stop by Operate DeviceNet Interface (2) close all the handles. Please see the example Get Identity Attribute.

Regards,
Frank